001    /*
002     * Licensed to the Apache Software Foundation (ASF) under one
003     * or more contributor license agreements.  See the NOTICE file
004     * distributed with this work for additional information
005     * regarding copyright ownership.  The ASF licenses this file
006     * to you under the Apache License, Version 2.0 (the
007     * "License"); you may not use this file except in compliance
008     * with the License.  You may obtain a copy of the License at
009     *
010     *     http://www.apache.org/licenses/LICENSE-2.0
011     *
012     * Unless required by applicable law or agreed to in writing,
013     * software distributed under the License is distributed on an
014     * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015     * KIND, either express or implied.  See the License for the
016     * specific language governing permissions and limitations
017     * under the License.
018     */
019    package org.apache.shiro.crypto.hash.format;
020    
021    import org.apache.shiro.crypto.hash.Hash;
022    
023    /**
024     * A {@code HashFormat} is able to format a {@link Hash} instance into a well-defined formatted String.
025     * <p/>
026     * Note that not all HashFormat algorithms are reversible.  That is, they can't be parsed and reconstituted to the
027     * original Hash instance.  The traditional <a href="http://en.wikipedia.org/wiki/Crypt_(Unix)">
028     * Unix crypt(3)</a> is one such format.
029     * <p/>
030     * The formats that <em>are</em> reversible however will be represented as {@link ParsableHashFormat} instances.
031     *
032     * @see ParsableHashFormat
033     *
034     * @since 1.2
035     */
036    public interface HashFormat {
037    
038        /**
039         * Returns a formatted string representing the specified Hash instance.
040         *
041         * @param hash the hash instance to format into a String.
042         * @return a formatted string representing the specified Hash instance.
043         */
044        String format(Hash hash);
045    }